1. Field of the invention
The present invention relates to an industrial-scale preparation of a lactosucrose high-content powder and use of said powder, and, more particularly, to a preparation of a lactosucrose high-content powder comprising allowing a saccharide-transferring enzyme to act on an aqueous solution containing sucrose and lactose, removing concomitant saccharides from the resultant saccharide solution containing lactosucrose to obtain a lactosucrose high-content solution with a lactosucrose content of 45 w/w %, on the dry solid basis (d.s.b.), or higher on sugar composition ("w/w %, d.s.b." will hereinafter be designated as "w/w %" if not specified otherwise), and spray-drying the lactosucrose high-content solution into a powder; and to an orally- or parenterally-administrable product in which the powder is incorporated.
2. Description of the prior art
Lactosucrose is a trisaccharide consisting of galactose, glucose and fructose, and has the chemical structure
by O-.beta.-D-Gal-(1.fwdarw.4)-O-.alpha.-D-Glc-(1.rarw.2)-.beta.-D-Fru (wherein "Gal", "Glc" and "Fru" mean galactose-, glucose- and fructoseresidues). As described in Japanese Patent Publication No.53,835/84, the lactosucrose has been known for an extremely useful saccharide as a selective saccharide source for a microorganism of the genus Bifidobacterium.
It has been known that lactosucrose can be prepared by allowing a saccharide-transferring enzyme such as a fructose-transferring enzyme or a galactose-transferring enzyme to act on an aqueous solution containing sucrose and lactose. The fructose-transferring enzymes which have been advantageously used in conventional preparation include, for example, a levansucrase derived from a microorganism such as those of the genera Bacillus and Aerobacter as described in Japanese Patent Publication Nos.58,905/82 and 53,835/84; and a B-D-fructofuranosidase derived from a microorganism of the genus Arthrobacter such as a microorganism of Arthrobacter sp. K-1 (FERM P-3192) as described in Japanese Patent Application No.160,660/89 which had been applied to Japanese Patent Office on June 26, 1989 by the present inventors Arthrobacter sp. K-1 was deposited at the Fermentation Research Institute, Agency of Industrial Science and Technology, Ministry of International Trade and Industry, 1-3, Higashi, 1 chome, Tsukuka-shi, Ibaraki-ken 305, Japan, on May 19, 1989. The galactosetransferring enzymes which have been advantageously used in conventional preparation are present, for example, in a microorganism of the genus Sporoboromyces as described in Canadian Journal of Chemistry, Vol. 43, pp. 2,259-2,264 (1965) and Japanese patent laid-open No. 85,090-89, and in a microorganism of the genus Rahnella as described in Japanese Patent Laid-Open No.35,095/90. Intact cells or extracts of such microorganisms can be advantageously used.
It was confirmed that though the content of lactosucrose in a product produced by allowing the enzymes as described above to act on an aqueous solution containing sucrose and lactose was generally in the range of about 5-30%, d.s.b., on sugar composition, we could only obtain an unstable powder which readily absorbed moisture and readily solidified to lose its free-flowing ability even when the product was directly dried and pulverized.